#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int Factorial(int n)
{
	if (n == 1)
		return 1;
	return n * Factorial(n - 1);
}
int main()
{
	int n = 0;
	scanf("%d", &n);
	printf("Ľ׳Ϊ%d\n", Factorial(n));
	return 0;
}